a1 (From the Lister Institute, London.)
The rapid fall in the number of plague cases with the onset of hot weather is a characteristic feature of plague epidemics in the northern half of India. In these regions the rise in temperature is accompanied by an increased drying capacity of the atmosphere so that it is impossible to assess to what extent the higher temperature and increased drying power are respectively responsible for the effect.
1 The experiments recorded in this paper were made in 1914. The work was put aside during the war. For various reasons, amongst them the death of Arthur Bacot, who contracted typhus whilst experimenting with infected lice, the observations have not been recorded until now.